The present invention relates generally to gearboxes and, more particularly, to a device for a multi-stage gearbox including at least one shifter rod which is engageable by at least one locking element for locking it in position when it is in a predetermined position, and to a method of operating same.
A device for a multi-stage gearbox of this type is known from DE 22 23 553 A1. Therein, an immobilizing element for arresting the shifter rod in a predetermined position is provided in addition to a locking element. This arrangement requires a greater amount of space because the immobilizing element is effective on the shifter rod at right angles to the locking element. Moreover, the shifter rod has to be constructed so that the arresting force imposed by the immobilizing element can be properly applied. This arrangement is relatively expensive, especially when there are more than two shifter rods.
A gear blocking arrangement for a gearbox is known from DE 196 47 788 A1 in which a shifter rod is surrounded by a latching-sleeve having depressions spaced around its periphery. These depressions serve firstly for accommodating a locking element and secondly, for accommodating an immobilizing element. A disadvantage of this gear blocking arrangement is that it requires a relatively large amount of space due to the provision of the latching element on the one hand, and due to the immobilizing element being displaced by an angle of 180.degree. around the periphery of the latching element on the other.